Pole-shoe tool



Sept. 8, 1953 r J. 1-. BECKER POLE-SHOE TOOL 2 $heets-$heet 1 Filed June20, 1951 J. T. BECKER POLE-SHOE TOOL Sept. 8, 1953 2 Sheets-Shee t 2Filed June 20, 1951 p/leoeui or I f e a f Patented Sept. 8, 1953 jUNITED STATES PATENT OFFICE v v f 2,651,338 PLE-SH( )E- TOOL Joseph T.Becker, Chicago, Ill. Application-June 20, 1951, Serial No. 232,573

This invention is concerned with improvements in the construction of atool-adapted particularly for use in replacing or removing-pole-shoes ofautomotive generators and starting motors.

In a generator or starting herein concerned, the field coils are Wrappedaround the pole-shoes and the pole-shoes are held in place by means ofpole-shoe screws. It is essential that the pole-shoe screws be drawn upvery tightly in order to maintain proper clearance between the fieldcoils and the armature. Electrical machinery ofthis type is relativelyexpensive and should the field coils burn out, as often occurs afterlong use of the motor, it is desirable to replace the burned out coilswith new ones by removing the pole-shoes from the frame, therebysaving'the cost of a new motor or generator. The pole-shoe screwsordinarily are difficult to remove because they must be securelytightened and likewise they are difiicult to draw up tightly in order tomaintain correct clearance between the field coils and the armatures.Obviously, great care must be exercised not to damage the pole-shoescrew head or the frame when-removing and replacing the poleshoes.Specially designed tools have been provided for this purpose which areintended to exert vertical pressures on the pole-shoe screw while sameis being turned. These tools in the main are large, bulky and made andsold as specialized units and" hence not adapted for use withconventionally available equipment such as an arbor press which iscapable of easily exerting great vertical pressures.

Accordingly, it is a principal object of this invention to-provide apole-shoe tool of the character described adapted to be used with anarbor press or the like for removing and replacing poleshoes ofgenerators or starting motors.

Another object of the invention is to provide a tool of the characterdescribed which isinexpensive to manufacture; simple and easy to use,which provides for rapid and safe removal and replacement of thepole-shoes and which is durable. y

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel features.of construction, arrangement and a combination vof parts hereinafter.fully described, illustrated in the accompanying drawings, andparticularly pointed out in the appended claims, it being understoodthat various changes in the form, proportion, size and minor details ofthe structure may be made without departing from the spirit motor of thetype I expensive constructions 3, claims. (01. '144 s2),

I2 is formed on the upper end of the 2 or sacrificing any of theadvantages of the invention. i

For the purpose of facilitating an understanding of this invention;there is-illustrated in the accompanying drawings a preferred embodimentthereof, from an inspection of which, when considered in connection withthe following descrip-'- tion, this invention, its mode of construction,assemblyand operation, and many of its advantages should be readilyunderstood andappreciated.

Referring to the drawings in which the same characters of reference areemployed to indicate corresponding or similar parts throughout theseveral figures of the drawings: I

Fig. 1 is a perspective view of an'arbor press having the pole-shoe toolembodying the invention associated therewithand showing the manner inwhich said press and tool may be operated for removing or replacing apole-shoe. Fig. 2 is an elevational view of the arbor press andpole-shoe embodying the invention as shown in Fig. 1 and having portionsthereof in section to show construction details.

Fig. 3 is a sectional view through the pole-shoe tool taken along theline 33 of Fig. 2 and in'the direction indicated, with parts broken awayto show certain details. v

Fig. '4 is an elevational view of the pole-shoe tool embodying thisinvention.

Fig. 5 is a top plan view of the pole-shoe tool embodying thisinvention.

Fig. 6 is a bottom plan view of the pole-shoe tool embodying thisinvention.

Referring to the drawings, the reference character l0 designatesgenerally an arbor press with which my tool is adapted to be associated.Only those portions of the press I 0 which'are pertinent to anunderstanding of the invention have been shown, it being understood thatthe size and construction thereof may be varied and that the press perse forms no part of the invention. Same has a vertical frame llordinarily supported at its lower end on a base (notshown).

v press, said housing having the operating parts for exerting verticalpressures contained therein. Protruding from said housing isa rod I3which is adapted to be reciprocated vertically over a table II securedon the frame. I have shown generally'a ,handle l5 secured to the housing12 by means of,

be reciprocated vertically.

known means such as a foot-operated treadle or suitable electrical meansalso would be apprepriate for this purpose. I provide a suitably shapedgrooved block 16 adapted to rest upon the table and support thereon aframe 11 in position to have the pole-shoe thereof removed. Referring toFig. 1, I have shown the frame I! in position on the base or block I6with the poleshoe screw l8 disposed directly beneath the rod l3 andfacing same. The head IQ of said screw is provided with a slot and whenthe screw is tightened it is disposed within the countersunk opening inthe outer casing 212 of the motor. The pole-shoe tool embodying theinvention is designated generally 23. Same has a circular cap member 24comprising a top wall 25 and a side wall 26 defining a central cavity 21therebetween. A ball-bearing unit is force-fitted in said cavity, withthe outer race 38 disposed against the inner surface of the wall 26. Iprovide a shaft having an upper portion 29 adapted to be received in thecentral bore 30 of the inner race 3| of said ball-bearing, and arectangular body portion 32 integrally formed with said portion 29. Thebody portion 32 extends downwardly from said cap member. A seal 33 ismounted in the cap member against the. :ballbearing unit and a springclip 34 engaged in annular groove 34' on the inner surface of the wall26 keeps the ball-bearing unit and lubricant .inthe cap member.Thus,.the shaft portion is .adaptedto rotate freely in the cap member24.

The lower end of the body portion 32 is provided with averticallyarranged slot 35 between the vertical walls and 31. A screw driver bit33 is adapted to be received in said slot and fastened therein by -meansof a set screw 33 threaded into the opening in wall 35. A spring detentdevice 4| is mounted in the recess 42 above the slot 35 and includes aball 43 having a portion thereof protruding from the recess 42. Themanner in which the herein described tool is operated may best be-seenfromFigs. 1 and 2. .The motor 11 is placed in position on the base I6 sothat the polehoe screw i=8 isopposite the rod 13. Abit 38 is selected;which has a tapered end 44 appropriate for engagement in the slot 20 ofthe pole-screw l8 and secured in the slot 35 of the tool. The tool ispositioned with the tapered end 44 ot the bit in the slot 20 and thehandle 15 is manipulated to drop the rod 13 into engagement with theupper surface 45 of the cap 24. A ratchet wrench 46 of conventionalconstruction which has previously been inserted over the body portion3Zis. heldin place by means of the detent device 41. In Fig. 2, the toolis shown in position to remove the pole-shoe screw F8. The handle I5 ismanipulatedto cause the rod l3 to bear down on the cap 24 therebyexerting a tremendous vertical pressure on the head IQ of the screw [8.The ratchet wrench 46 is easily turned in a clockwise directionindicated at" at the same time that the press I0 is exerting a verticalpressure on the screw l8. Thus, at all times that the screw I8 is beingturned a tremendous vertical pressure is being exerted thereon by meansof the arbor press so that the screw may be removed easily and quicklywithout damage to the screw head [9 or the frame of the generator orstarting motor IT.

It will be apparent that I have provided a poleshoe tool which by reasonof its being capable of association with a machine such as an arbor 4press, permits the easy and rapid removal and replacement of thepole-shoe of generators or starting motors. The efficient operation ofdevices of this type depends in great measure on having a tremendousvertical pressure exerted on the head of the pole-shoe screw as thescrew is being turned. By providing a pole-shoe tool capable of beingassociated with an arbor press, and used with a simple ratchet wrenchefficient removal of pole-shoe screws is insured and the bulkyand'expensive frames heretofore used in devices of this type areeliminated.

-It is believed that the invention has been sufficiently describedwithout any necessity for further details and it is to be understoodthat many variations are possible without departing from the spirit ofthe invention as defined in the appended claims.

a What is claimed and desired to be secured by Letters Patent of theUnited States is:

1.- A tool-for removing pole-shoes from motors having said'shoes securedtherein by means of pole-shoe screws, the tooladapted to be used incombination with a press having a reciprocal member capable of exertingsubstantial vertical pressure, said tool comprising a cap member havinga top wall of substantial thickness and side walls deflninga downwardlyopening cavity therebetween, a ball bearing unit forcefitted into saidcavity having an inner and outer race, a shaft member having a reducedend portion supported in said inner race and a body portion on itsopposite end depending from said cap, said body portion having avertically arranged slot in the free endv thereof and a screw-driver bitremovably secured. therein, said shaft adapted to receive a ratchetwrench thereon ior turning the same, said top wall arranged against thereciprocal member with a said bit-engaging a pole- .shoe screw wherebysaid tool may have said pressure exertedagainst the cap membersimultaneously as the tool: is being turned. by said wrench. v p I 2. Atool as described inclaim lin which said outer race is disposed againstthe inner surface of saidside walls whereby said shaft member may berotated ireely insaid cap member.

3, A tool as described in claim 2 in which said side walls have anannular groove on the inner surface thereof and a spring clip retained.in said groove for holding said unit in said" cap member and a seal-vmember in said cap member arranged between said unit and sp ng clip;

7 y T. BECKER.

References Cited. iii-the file of this patent 'UNITED' STATES PATENTSNumber Name Date 346,058 Mouat' July 20, I886 1,683,484 Post Sept. 4,192a 1,724,491 Mandi Aug. 13, I929 1,772524 Siedemann Aug. r2, r93012,829,557 nwmg' otter, Iss1 zeraese Shaker Sept. 16-, 195': 2,623,556Henry Dec. $6, 1952 "2,626,641 Marten i Jan. 2?, i953 OTHER REFERENCESCatalog fQ," :Snan-Orr Tools Corporation of ,Kenosha, Wisconsin; issued-D'ecember 15",. 19441.

